I went to an auto hobby shop today to put on my sway bars and headers. The guy that works there looked at my headers laying on the floor, then he picks one up and looks at the discoloration from the heat. Then he says "you're running lean." I didn't have much time, plus the guy is very talkative so I didn't ask what he meant. I know what lean in a/f ratio means, that obvious....I think. Anyone have an idea?

 

he looked at the discoloration and could tell you were running lean? Never heard that.

 

Yep, you can tell by the colors. I can't remember what colors indicate what if my life depended on it, but I know you can tell from it.

 

white/grey = lean
black/brown = rich

What's funny is from what I've read on this board, our cars are set to run rich from the factory. I'd get another opinion on that from a certified mechanic or dealer.

 

Come to think of it, pull out the spark plugs and see if you've got that same discoloration on them.

 

my car was runing richer after headers..u can see all the black exhaust build up in the tips....

 

That discoloration came from when the headers were on my TLS which I traded in back in Feb. Slightly off topic how would running lean affect 1/4 times?

 

My car got some unbelievable 60 foot times, but horrible et's. would that be the result of running lean?